Airplane construction



G. H. CURTISS.

AIRPLANE CONSTRUCTION.

APPLICATION FILED APR. 5. ms.

Patented Feb. 15, 192-1.

3 SHEETSSHEET 2.

G. H. CURTISS; AIRPLANE CONSTRUCTION. 'Armcmou men APR. 5. 1913.

1,368,549. Patented Feb. 15,1921.

3 $HEE'T5SHEET 3- INVENTOR Gum N H .Cuzn s5.

ATTORNEY.

V UNITED 'STAT lrear- OFFICE.

GLENN H. CUBTISS, OF GARDEN CITY, NEW YORK, ASSIGNOR TO CURTISS AEROPLANE AND MOTOR CORPORATION, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

AIRPLANE CONSTRUCTION.

Specification of Letters Patent.

Patented Feb. 15, 1921 Original application filed December 22, 1916, Serial No. 138,499. Divided and this application filed April 5, 1918. Serial No. 226,861.

To all whom it may concern Be it .known that I, GLENN H. CURTISS, a citizen of the United States, residing at Garden City. in the county of Nassau and State of New York, have invented certain new and useful Improvements in Airplane Construction, of which the following is a specification.

My invention relates to airplanes and is a division of application Serial No. 138,499, filed December 22, 1916. The characteristic of the invention is the arrangement of the supporting surfaces respectively above and beneath the fuselage. The lower supporting surface is so arranged or positioned that its wing beams or spars lie close up under the fuselage. They are directly attached to the longrons of the fuselage at their points of intersection with them. Accordingly the lower surface (also the upper surface) may be constructed as a unit with a resulting decrease in production cost. Moreover, supporting surfaces thus constructed and attached or fastened are stronger and better in that the factor of safety is raised.

The invention is further characterized by various constructional features. These features include improved fastenings for the wings. One of these fastenings 1s provided at the points of attachment of the upper supporting surface with the wing posts .or struts, another at the points of attachmentof the forward wing beams of the lower supporting surface with the longrons of the fuselage, and still another at the points of attachment of the rear wing beams of the lower supporting surface with said longrons. In each instance the fastening devices are inclosed and consequently removed from view. Further constructional details and refinements will be hereinafter set forth.

Of the drawings, wherein like characters of reference designate like or corresponding parts v Figure 1 is a side elevation of the airplane.

Fig. 2 is a front end elevation.

Fig. 3 is an elevation of the fuselage assembly, the landing gear and the supporting planes.

Fig. 4 is a view illustrating in section the upper wing construction and the manner in which the wing posts are fastened.

Fig. is a similar View illustrating the connectlon between the wing post and the lower wing.

Fig. is a detail section illustrating the connection between the forward wing beam and thc lower longcrons of the fuselage.

Fig. 7 is a similar view illustrating the connection between the rear-wing beam and said longrons.

Fig. 8 is a section on the line 88 of Fig. 6.

Fig. 9 is a detail view of the connection betiween the wing post and the upper wing, an

Fig. 10 is a. similar view of the connection between the wing post and the lower wing.

In the embodiment of the invention selected for illustration, 30 designates as an entirety, the fuselage or body of the craft, 31 the motor, 32 the propeller and 33, as an entirety, the landing gear.

The supporting surfaces or wings of the airplane I have designated respectively and 56, the former 55 having the greater span. Both wings or planes (the machine being of the biplane t pe) extend transversely across the fuse age at the engine section thereof, one above and the other below the longrons. A total elimination of all lift and drift wires intermediate the planes may be described as a fundamental characteristic of the machine.

In addition to the center wing posts 43 and 49, there are but two wing posts, the

said posts being arranged respectively symmetrically at opposite sides of the fuselage 30, each post extending at an oblique angle to the supporting planes with the lower terminals of respective post? in closer proximity to the sides of the fuselage than the" opposite extremities thereof.

In construction, it will be noted (see Figs. 4 and 5) that the Wing posts, each designated as an entirety by the numeral 57, comprise coextensive parallel tubular parts. The coextensive parts of each wing post are longitudinally spaced throughout, the forward part, designated 58 being constructed of metal tubing and the after part, designated 59, being similarly constructed and rearwardly braced as indicated at 60 at its respective terminals to distribute or increase the wing-engaging area of respective posts. By arranging the parts 58 and 59 in tandem formation, both said parts may be streamlined as a unit. (and also the braces 60); fabric such as linen being used.

Both wing ljicams of the supporting surfaces are of the box-beam type, the forward wing beams 61 comprising a plurality (preferably four) of connected parts. The rear wing beams 62 may be also described as box-beams although in cross section the said beams are comparatively flat and interiorly reinforced by partitions running longitudinally of the beams throughout substantially their full length. Said beams may be accordingly described as hollow and built up to secure strength and lightness. Beams of this form are better able to withstand the drift stresses incident to flight. In other respects both supporting surfaces 55 and 56 are quite similar to the supporting surfaces now in use except in. so far as the number of wing frame parts is concerned. These parts it will be noted, have been appreciably re duced.

Compression tubes or members 63 interbrace the beams of each wing. These compression members are located respectively equidistant from the ends of the upper wing or plane, adjacent the terminals of said upper plane (in the plane of the wing post 57) and adjacent the terminals of the lower plane (adjacent the opposite terminals of said post).

To secure a rigid foundation of increased area for the respective wings at the wing posts. longitudinally grooved devices or channel bars 67 are provided. These devices or channel bars are formed integrally upon the respective terminals of the oblique Wing oosts 57 to engage the respective compression members throu hout the major portion of their length. fhe point of engagement is in this way distributed both ore and aft. Gusset plates 68 brace the respective devices, each lying almost entirely in the confines of the adjacent wing.

As a fastening means for the wing posts, cars 69 are formed on the grooved device or channel bar 67 at the upper extremity of said post and inverted U-bolts 70 arranged to extend therethrough. Said bolts 70 embrace the compression members of the upper wing and thus constitute the wing post fastening means. the U-bolt terminals (see Fi 9).

At the lower extremityof the wing posts the fastening means is substantially the same as the fastening just disclosed. At this end, however, U-bolts 70 are eliminated. Braces 72 interconnect the lower supporting surface 56 in the plane of the wing posts 57 Nuts 71 are threaded on 'with the landing gear axle 51, the braces bolts 73 penetrate cars 74 formed at the foot of each wing post 57- and ears 75 formed at the upper extremity of each diagonal brace 72. Said braces 72 are equipped with channeled bars or devices 76 and gusset plates 77 quite similar to the corresponding elements previously described. For an understanding of the arrangement just disclosed, reference should be had to Figs. 5 and 10.

The wing beams of the lower supporting surface 56, as stated,-extend transversely across the fuselage below the lower longerons to which they are fastened. The forward wing beam of the lower wing lies in the vertical plane of the rear leg of the forward fuselage post-42 and the-rear wing beam in the vertical plane of the rear fuselage post 48. Each wing beam is secured to the lower longrons -of the fuselage in. the immediate vicinity of said posts, thesecuring means for the forward wing beam contacting the longrons, at points respectively fore and aft of the forward fuselage posts and the securing means for the rear wing beam at a point aft only of the reef fuselage posts. Said fastening means in each instance may be described as comprising inverted U-bolts 78. The U-bolts for the forward wing beam (of which there are fourtwo for each longron) do not penetrate the beam but engage therewith respectively atopposite sides thereof. The bolt extremi' ties so engage an especially provided fitting 79 as to retain the fitting firmly in place against the metal portion 41 of the lougrons. The fitting 79 for each longron comprises an upper bearing plate 80, a lower bearing plate 81 flanged as indicated at 82, and ii termediate sleevelike devices 83, the latter terminally abutting the spaced plates and S1 to prevent disrupture of the beam. A bolt 84 is utilized as the fastening means for the plate 81. Circumferentially. extending retaining flanges 85 prevent displacement of the U-bolts 78.

Although generally similar the fastening means for the rear wing spar or beam 62 is somewhat different from the fastening just disclosed. By reason of the depth of the rear wing beam it is entirely practical to extend the extensions of the Ubolt 78 transversely therethrough. A fitting 86 flanged as at 87, however, is interposed between said beam and the lower longrons of the fuselage to provide a foundation in form corresponding to the shape of the longrons at the point superposed sup eeann where the U-bolts 7 8 eng'a e. The fastenings for the respective wing cams have been detailed in Figs. 6, 7 and 8.

It will be noted from the structure disclosed that exposed surfaces have been eliminated in so far as possible andinclosed devices substituted to insure strength. This is particularly true as regards the wing structure which is stripped of all lift and drift wires. For obvious reasons the wing beams of the lower wing extend uninterruptedly beneath the fuselage without a break in their continuity. By this arrangement the lower supporting surface is strengthened without increasing the number of its parts.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art after understanding my invention, that various changes an modifications may be made therein without departing from the spirit or scope thereof, I aim in the appended claims to cover all such modifications and changes.

What is claimed is:

1. In an airplane, the combination with the fuselage, of a. wing structure including rting surfaces, one of the supporting sur aces being extended across and beneath the fuselage, close up against the under side thereof, wing beams incorporated in the supporting surfaces as structural elements thereof, the continuity of the wing beams at the fuselage being unbroken, and meansfor fastenin the supporting surfaces directly against t e under side of the fuselage.

neath and close up against rectly against t e 2. In an airplane, the combination with the fuselage, the fuselage including longron-s and vertically extending fuselage struts, of a supporting surface extended intermediately across the fuselagp directly bet e lower longrons thereof, wing beams incorporated in the supporting surface, said beams being located directly beneath the verticall extending fusela e struts and fastened di lower longrons.

3. In an airplane, the combination with the fuselage, the fuselage including longrons and vertically extending fuselage struts, of a supporting surface extended intermediately across the fuselage beneath and close up against the under side thereof, win beams incorporated in the supporting sur ace, said beams being located directly beneath the vertically extending fuselage struts, and means for fastening the supporting surface to the fuselage including separate fastening devices directly connecting with the longmns and located respectively at opposite sides of certain of the fuselage struts.

4. In an airplane, the combination with fuselage struts, means the fuselage, the fuselage including longrons and vertically extending fuselage struts, of a supporting surface extended intermediately across the fuselage directly beneath the lower longrons and close up against the under side of the fuselage, wing beams incorporated in the supporting surface, said beams being located closely adja cent to the vertically extending struts, and fastening means for the supporting surface including inverted U-bolts arranged upon opposite sides of the fuselage struts to embrace the longrons and extend beneath the wing beams of the supporting surface.

5. In an airplane, the combination with the fuselage, the fuselage including lonof a supporting grons and fuselage struts,

surface extended mtermediately across the fuselage directly beneath and close up against the under side thereof, wing beams incorporated in the supporting surface, said beams being located closely adjacent to the for fastening the the longrons, and means on wing beams to for holding the fastening the longrons means in place.

6. In an airplane, the combination with the fuselage, the fuselage including longrons as structural elements thereof, of a supporting surface extended intermediately across the fuselage directly beneath and close up against the under side thereof, wing beams incorporated in the supporting sur ace, fittings interposed between the wing beams and the longrons, and fastening means for the supporting surface connecting with the longrons, the arrangement of the fastening means being such that the fittings are clamped tightly between the wing .beams and the longrons.

7. In an airplane, the combination of superposed supporting surfaces, the supporting surfaces including wing beams as structural elements thereof, compression members incorporated in the supporting surfaces, wing struts interconnecting adjacent supporting surfaces, channel bars formed upon the strut ends to receive the compression members, and means for fastening the channel bars and compression members together.

8. In an airplane, the combination of superposed supporting surfaces, each supporting surface including wing beams as structural elements thereof, compression members incorporated in the supporting surfaces, wing struts interconnecting adjacent supporting surfaces, channel bars formed upon the strut ends to receive the compression members, gusset plates formed upon the wing struts to brace the channel bars from beneath, and means for fastening the compression members and channel bars together.

9. In an airplane, the combination of superp porting surface includi structural elements th members extended from one to the Wing; one to the other of the su gues plates formed on th strmsto underlie the col and brace the and aft direct plates being brace the Wing tion of their length, and

osed supporting surfaces, each suping the gusset plates to the compression 15 ng wing beams as members. I

compression 10. In a strut, brace spar or the like for the other of airplanes, the combination of a longitudibeams. wing struts extended from nally channeled terminal portion integrally pporting surfaces, formed upon and extended transversely 20 e ends of the wing across one end of the strut and a reinforcnpression member ing gusset plate fastened respectively to the supporting surface in a fore underneath faces of the terminal portion ion from beneath, the gusset and to the trailing edge of the strut. longitudinally elongated to In testimony whereof I hereunto affix my 25 a substantial porsignature. means for fasten- GLENN H. CURTISS. 

